All Oracle Error Codes
Oracle DBA Forum

Frequent Oracle Errors

TNS:could not resolve the connect identifier specified
Backtrace message unwound by exceptions
invalid identifier
PL/SQL compilation error
internal error
missing expression
table or view does not exist
end-of-file on communication channel
TNS:listener unknown in connect descriptor
insufficient privileges
PL/SQL: numeric or value error string
TNS:protocol adapter error
ORACLE not available
target host or object does not exist
invalid number
unable to allocate string bytes of shared memory
resource busy and acquire with NOWAIT specified
error occurred at recursive SQL level string
ORACLE initialization or shutdown in progress
archiver error. Connect internal only, until freed
snapshot too old
unable to extend temp segment by string in tablespace
Credential retrieval failed
missing or invalid option
invalid username/password; logon denied
unable to create INITIAL extent for segment
out of process memory when trying to allocate string bytes
shared memory realm does not exist
cannot insert NULL
TNS:unable to connect to destination
remote database not found ora-02019
exception encountered: core dump
inconsistent datatypes
no data found
TNS:operation timed out
PL/SQL: could not find program
existing state of packages has been discarded
maximum number of processes exceeded
error signaled in parallel query server
ORACLE instance terminated. Disconnection forced
TNS:packet writer failure
see ORA-12699
missing right parenthesis
name is already used by an existing object
cannot identify/lock data file
invalid file operation
quoted string not properly terminated

Re: ORA-1555

Phil Singer


Sanjay Mishra wrote:
> Hi everybody
>  I have seen several time ORA-1555 error in few of the Prod Database. SOme of them have very big UNDO tablespaces. All are 9i Databases. What are the other option that need to be checked for such issue beside increasing the space as some of the database has UNDO tablespace around 50-150G
>  Is it good to create new undo tablespace and make it default in such scenario and later on dropped the old. Do somebody has set of UNDO checking query that can be ran at some particular point to really see if that big UNDO are really been used so that it can be resized.
>  I am thankful for any suggestion for monitoring such ORA-1555 as well as query to check UNDO segment space.
>  TIA
>  Sanjay

1) There are a number of good descriptions of this on the internet, but
the one's which come easiest to mind are to search asktom.oracle.com on

2) To add to what has already been said, an easy way to get this error
is to have a long running query going in the midst of a lot of short
transactions, all of which commit and update the rows you are querying.

3) Even more fun is to have a complicated Data Warehouse summarization
routine, which runs for several hours, which commits across an open
cursor (without closing the cursor).

Many find it counter-intuitive (I certainly did at first), but frequent
commits are the best way to get an ORA-1555, and using a minimum number
of commits the best way to avoid it (assuming you have the space).

Remember that in 9i UNDO_RETENTION is a strong plea rather than an
absolute command; if Oracle runs out of undo space it will reuse the
space as if the parameter were not set.

Phil Singer                 |  psinger1 at chartermi dot net
PhD, OCP, and All Around Good Guy  |  Do the Obvious to Reply